Session 1 Flashcards
What does the pericardium consist of?
(pericardial sac)
- Outer fibrous layer (parietal) which attaches to the sternum
- Inner serous layer attached to the heart (visceral layer).
- Pericardial fluid between layers to create a low friction environment
What does the fibrous layer of the pericardium do?
Keeps the heart in place through attaching to surrounding structures
Which is the preferred chest X ray;
AP/PA? Why?
When can’t the preferred be used?
PA- posterior to anterior
because AP magnifies the heart and widens the mediastinum
If the patient is very ill and unable to stand then AP must be used instead of PA
What is the mediastinum?
Which organ lies here?
Region in the thoracic cavity between the right and left pleural cavities (contain lungs)
The heart lies in the middle mediastinum
What rate of blood flow must be maintained to the brain?
750 ml/min
Name the valves which separate the atrium and ventricles.
How many cusps does each valve have?
Left side- mitral valve (2 cusps)
Right side- tricuspid valve (3 cusps)
What causes the valves to close as blood moves through the heart?
A small backflow of blood into the chamber that blood has just left
Where is the phrenic nerve on the heart’s surface?
Where is the nerve travelling?
What does the nerve inneravte?
- Right and left phrenic nerves on the lateral borders of the heart
- Towards the diaphragm
- Diaphragm and pericardium
What are the aortic sinuses?
How many does the heart have?
Name them and explain what arises from each.
Dilations on the ascending aorta
3
Left aortic sinus- left coronary atery
Right aortic sinus- right coronary artery
Non-coronary sinus (no vessels)
Describe the normal flow of blood in vessels
What does this mean?
laminar
adjacent layers of fluid slide over each other; flow in the central layers is fastest
What is a bruit?
(a vascular murmur)
Heard when there is turbulent flow in a vessel
Which type of muscle is multinucleated?
Which type of muscle has intercalated discs between cells?
Skeletal
Cardiac
In which muscle types is contraction regulated by calcium binding to troponin?
skeletal
cardiac
Stab victim to heart is tachycardic, has a low blood pressure and bulging jugular veins- why?
Heart rate is high to try and maintain blood pressure (fallen due to blood loss)
Blood pressure is low because the heart cannot fill properly as the time for diastole is reduced (tachycardic)
Bulging veins due to backlog of blood in the venous system as the heart is not filling
What can cause a pericardial effusion?
How does the heart sound in this case?
(fluid around the heart)
- pericarditis (infection)
- blood leaking for a weakened heart wall (previous MI)
sounds are soft and distant due to fluid
